Specifically I think Rand is going to have to sacrifice himself with a certainty that he WILL die. I have no clue how that may work, but I can't shake the feeling that Rand will have to have some sort of true death of a voluntary nature (Christ-like). Him simply passing back and forth into Moridin's body doesn't seem to have that level of sacrifice a "savior" figure needs. I think you are correct about Moiraine/Nynaeve/Rand/Callandor and likely someone will use the Dull Blade to avoid notice at some point, but I'm not 100% convinced it'll be Alivia or for the purpose you put forth.